Venom & Mimicry
by laika24 on April 6, 2017 - 9:23pm
Venom systems have evolved on multiple occasions across the animal kingdom, and they can act as key adaptations to protect animals from predators [ 1 ]. Consequently, venomous animals serve as models for a rich source of mimicry types, as non-venomous species benefit from reductions in predation risk by mimicking the coloration, body shape, and/or movement of toxic counterparts [ 2–5 ]. The frequent evolution of such deceitful imitations provides notable examples of phenotypic convergence and are often invoked as classic exemplars of evolution by natural selection. Here, we investigate the evolution of fangs, venom, and mimetic relationships in reef fishes from the tribe Nemophini (fangblennies). Comparative morphological analyses reveal that enlarged canine teeth (fangs) originated at the base of the Nemophini radiation and have enabled a micropredatory feeding strategy in non-venomous Plagiotremus spp. Subsequently, the evolution of deep anterior grooves and their coupling to venom secretory tissue provide Meiacanthus spp. with toxic venom that they effectively employ for defense. We find that fangblenny venom contains a number of toxic components that have been independently recruited into other animal venoms, some of which cause toxicity via interactions with opioid receptors, and result in a multifunctional biochemical phenotype that exerts potent hypotensive effects. The evolution of fangblenny venom has seemingly led to phenotypic convergence via the formation of a diverse array of mimetic relationships that provide protective (Batesian mimicry) and predatory (aggressive mimicry) benefits to other fishes [ 2, 6 ]. Our results further our understanding of how novel morphological and biochemical adaptations stimulate ecological interactions in the natural world.
I chose this article about fangblennies because I think it's really interesting that organisms can evolve to mimic others because they find it advantageous in their environment. Fangblennies are really cool because they actually evolved canines then evolved the venom, which in turn caused the canines to transform into venom delivery nodules. This particular venom also doesn't kill its recipient, it just slows its blood pressure down about 40%. This was to use in defense and not to capture food.
This is really cool to me because it shows how genes change based on the natural environment. The summary and also entire research text is really well put together and is clear about the information being presented. I think all of the ideas are strung into a coherent line.
This might offer some technologies in the future with regards to anti-venoms because the venom only drops blood pressure, it doesn't kill the recipient. This could be used in areas where venomous organisms reside.
The Evolution of Fangs, Venom, and Mimicry Systems in Blenny Fishes. Casewell, Nicholas R. et al. Current Biology , Volume 0 , Issue 0
The importance of being genomic: Non-coding and coding sequences suggest different models of toxin multi-gene family evolution. Malhotra, A., Creer, S., Harris, J.B., and Thorpe, R.S. Toxicon. 2015; 107: 344–358